Intermediate transfer members are well known and are widely used in electrostatographic imaging machines. A seamless intermediate transfer member (ITM) is desirable because it results in enhanced machine productivity for a wide variety of paper formats. Furthermore, a seamed ITM requires hardware for seam detection and increases the difficulty of cleaning the ITM. However, the cost associated with manufacturing a seamless ITM is high, especially for large circumference members.
The advantages of intermediate transfer members with more than one layer are discussed in the published literature. Multilayer ITMs can improve the quality of imaging because different layers can be designed to optimize specific functions of the imaging process. For example, a top layer may be optimized for toner release while the substrate layer may be optimized for its mechanical and electrical properties. An additional layer between the top layer and the substrate may be compliant so as to reduce image artifacts and improve transfer to certain paper types that are rough or textured. The use of compliant layers and release layers to improve transfer are described in U.S. Pat. Nos. 5,084,735 and 5,370,961. Also disclosed is the mold cast system used to produce a multilayer ITM. In order to meet image quality requirements of a typical electrostatographic machine, the ITM often has tight mechanical tolerances on features such as thickness, run-out and/or roughness, so as to minimize variations in machine operation such as overdrive and nip widths. In addition, the surface of the ITM must have low roughness. The grinding operation needed to make a multilayer ITM with the specified mechanical tolerances is a lengthy manufacturing step adding significant cost and time.
Mammino et al., in U.S. Pat. Nos. 5,298,956 and 5,409,557 disclose a process for manufacturing an intermediate transfer member having a reinforcing member embedded with filler material and electrical property regulating material. The reinforcing member described is composed of metal, synthetic material or fibrous material. The intermediate transfer member described has a thickness between 2 and 7 thousandths of an inch (0.05 to 0.175 mm).
U.S. Pat. No. 5,761,595 mentions the use of a multiple layer, carbon filled transfer component for improved transfer but makes no claim of imaging or transferring toner on top of the seam.
U.S. Pat. No. 6,457,392 refers to the method of making a seamless transfer belt using a puzzle cut punch and die system. The difficulties in manufacturing such a belt and the performance of such a belt are described in US Patent Publication 2006/0002746(A1).
Very long sheets of plastic or metal can be manufactured inexpensively in roll form using a continuous, high speed process. Therefore, the cost of a seamed substrate utilizing sheets cut from such a roll may be considerably less than the cost of manufacturing a seamless substrate (typically manufactured one piece at a time). For the reasons described above there exists a need for a low cost method to manufacture ITMs having a seamed substrate that can be used in electrostatographic machines where the seam area can be imaged upon without causing imaging artifacts or other difficulties.
One object of the present invention is to provide a process or manufacturing method to produce an intermediate transfer member that minimizes costly finishing steps such as grinding and conditioning. Another object of this invention is to provide a method of making an intermediate transfer member with a seamed substrate layer that does not adversely affect the image being transferred to or from its surface in the region of the seam. This improved intermediate transfer member allows for a uniform, uninterrupted first electrostatic transfer of a toner image from a primary imaging device and a second electrostatic transfer from intermediate transfer member to a receiver utilizing the whole transfer member including the seamed area. This improved intermediate transfer member also allows for enhanced machine productivity over a wide range of receiver sizes due to the ability to utilize the whole transfer member including the seamed area.